/**
 ***************************************************** 
 * @方法简介： 转换文件大小(B/KB/MB/GB)
 * @参数列表： @param fileS
 * @返回值： String B/KB/MB/GB
 ***************************************************** 
 */
public static String formatFileSize(long fileS) {
	java.text.DecimalFormat df = new java.text.DecimalFormat("#.00");
	String fileSizeString = "";
	if (fileS < 1024) {
		fileSizeString = df.format((double) fileS)+ "B";
	} else if (fileS < 1048576) {
		fileSizeString = df.format((double) fileS / 1024) + "KB";
	} else if (fileS < 1073741824) {
		fileSizeString = df.format((double) fileS / 1048576)+ "MB";
	} else {
		fileSizeString = df.format((double) fileS / 1073741824)+ "G";
	}
	return fileSizeString;
}